If you’re comfortable editing your template, use the HTML button code on https://www.printfriendly.com/button
See where I added “CHANGE TITLE HERE”?
<script>var pfHeaderImgUrl = '';var pfHeaderTagline = '';var pfdisableClickToDel = 0;var pfHideImages = 0;var pfImageDisplayStyle = 'right';var pfDisablePDF = 0;var pfDisableEmail = 0;var pfDisablePrint = 0;var pfCustomCSS = '';var pfBtVersion='2';(function(){var js,pf;pf=document.createElement('script');pf.type='text/javascript';pf.src='//cdn.printfriendly.com/printfriendly.js';document.getElementsByTagName('head')[0].appendChild(pf)})();</script>
<a href="https://www.printfriendly.com" style="color:#6D9F00;text-decoration:none;" class="printfriendly" onclick="window.print();return false;" title="<strong>CHANGE TITLE HERE</strong>">
<img style="border:none;-webkit-box-shadow:none;box-shadow:none;" src="//cdn.printfriendly.com/buttons/printfriendly-pdf-email-button-md.png" alt="Print Friendly and PDF"/></a>